• Question: Can enzymes be broken, a part from denaturing?

    Asked by 443cesk28 to Eoin, Ester, Natasha, Paul, Tom on 14 Nov 2017.
    • Photo: Paul McKeegan

      Paul McKeegan answered on 14 Nov 2017:

      Yes! That is a very cool biochemical question 🙂
      Enzymes can be broken and this is an important part of the normal role of many enzymes. You might have heard of enzymes called proteases, lipases or carbohydrases which break down protein, fats or carbohydrates. Enzymes are also proteins, so there are also certain proteases which can break down other enzymes! This is an important control, if a cell needs to switch an enzyme ‘off’ the best way might be to break it in two! This is a role carried out by organelles called lysosomes and proteasomes.

    • Photo: Eoin McKinney

      Eoin McKinney answered on 15 Nov 2017:

      They certainly can – great question. Enzymes have evolved to work at an optimal set of conditions, including temperature, pH, concentration etc. If these move away from that optimal level then the enzyme doesn’t work as well, although it isn’t completely ‘broken’. Denaturing typically involves extremities of those conditions and changes the way the enzyme protein is folded up, often irreversibly so it gets broken down and recycled within the cell. Enzymes are kept under control by other proteins in the body, too, though. Their function is inhibited by blocking proteins that keep them from doing too much. Many medicines target their function and block it which is another way they can be altered – I guess that can be called ‘broken’ as they are purposefully being prevented from working.

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